1. Lab Project GeoQuiz Spans the first six chapters of the text
You will create an application with a GUI user interface for a true/false application
This project introduces many of the basic concepts the apply to building and debugging Android applications
The technology changes fast; you’ll likely notice differences from the text. For example, I had to change vertical 24dp in the text to 60dp so text would not be hidden behind the action bar. I also had to move the left-right buttons from the right to the left; they were hidden by a mail icon.

2. GeoQuiz Screen Shots
Main Activity
Cheat Activity

4. drawable vs mipmap
Under the app/src/res folder, observe various mipmap folders
mipmap-mdpi, mipmap-hdpi, mipmap-hdpi, mipmap-xxhdpi
The text discusses various drawable folders
drawable, drawable-mdpi, drawable-hdpi, drwable-xhdpi, drawable-xxhdpi
Why the difference?
Device screen density don’t exactly match the provided densities
Drawable images scale up, when necessary, which can reduce quality
Mipmap Images scale down, preserving quality
Use mipmap for the launcher icon and application resized images
Use drawable for images used as-is, to avoid scaling overhead

5. Auto Getter and Setter Generation
Text variable naming conventions
Public non-static variables start with ‘m’
Public static variables start with ‘s’
Why? To avoid this.name = name in methods
To generate getters and setters
Right click after the constructor amd choose getters and setters
Result
The method names will include the ‘s’ and ‘m’
To avoid this: file=>settings->expand editor->expand code style->java->code generation and set field prefix to m and static field preference to s

6. Android Emulator Start the Emulator from Eclipse Important notes
Right click on the application
Select run as and then Android application
To debug: Select debug as and then Android Application
After the first time, just click the run icon at the top of the Eclipse window
Important notes
The emulator takes quite a bit of time to launch; be patient
Don’t shut down the emulator between application runs. Closing leads to long start up times, and sometimes confuses Studio
Every Studio run reinstalls and re-launches the application

7. Connect to Android Device
Requirements
Android tablet or phone
USB or micro-USB cable
Steps
Activate developer mode and enable device debugging
Settings->about device->tap build number seven times
Settings->applications->development->enable device debugging
Simply run from studio
Note for Windows: Acording to the text, you may have to install the ADB bridge and possibly have to install an appropriate device driver. I did not have to do this, so this may no longer be necessary.

8. Android Terminology
Component: Activities, content providers, broadcast receivers, and services that together make up an application
Application: A group of launchable components
Content Provider: A component that serves data to other applications
Broadcast receiver: Component receiving notifications from other activities
Service: Background component responding local or remote application requests
Context: Object containing the global state of an application environment
Intent: Asynchronous launching (or communication) message
Intent Filter: Criteria an Android device uses to find matching activities
Bundle: A set of key/value pairs used to persist the state of an activity

9. Android Terminology (cont.)
Preference: A key/value pair, which defines a user option
Context Menu: A menu executing after a long click
Long Click: Analogous to right clicks; Hold click for approximately two seconds
Modal: Dialog requiring a response before continuing an activity
Localize: Separate data from an application, so changes don't require changing source. Refer to the data by an identifier name.
Faded Edge: An edge of a scrollable area that is faded to indicate that more information exists
Fragment: An independent module launched without the manifest and tightly bound to an application to execute sub-tasks

10. Android Terminology (cont.)
Gravity: Determine alignment of text within a view of different size. Values can include: top, bottom, left, center, fill
Content Provider: Wrapping component for data, exposing data (SQL for example) to multiple applications, using a standard API.
Cursor: An object containing rows extracted from an SQL table
Projection: The columns of an SQL table of interest
Live Folder: Deprecated mechanism to display data on home page
Developers now use Widgets
Live: updates display automatically
Widgets: Miniature icon-based application view (clock, battery charge percent) embedded on the home screen or application
Live Wallpaper: Dynamic interactive home screen backgrounds

11. Intent Android Intent Resolver Types of Intents More Details later
Definition: Messages that asynchronously launch or communicate with other applications/activities
Android Intent Resolver
Applications sends intents to the Android system
The Android intent resolver searches all application manifests to find the most suitable matching activity
Intents can target a single application or multiple applications using broadcasts
Types of Intents
Explicit intents: Directly launch using class names
Implicit Intents: Launch based on criteria
Send/Receive information; launch activities
More Details later

12. The Manifest The new project wizard Purpose:
Automatically Creates a default AndroidManifest.xml file
Creates a default activity in the project directory
Purpose:
Register activities, services, content providers with launching intent filters
Request permissions
To alter the manifest: There are two possibilities
Edit the manifest directly
Use the Manifest Editor3

13. HelloWorld Manifest
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android=" package="com.paad.helloworld" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="1" // User cannot install if less (1=default) android:targetSdkVersion="15" /> // Verify features between min & target <application > <activity android:name=".MyActivity" > <intent-filter > <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> </manifest>
Some of the above no

14. Implicit Intent Filter Example
Note: An intent launches an activity
<intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter><intent-filter> <action android:name="android.intent.action.VIEW" /> <action android:name="android.intent.action.EDIT" /> <action android:name="android.intent.action.PICK" /> <category android:name="android.intent.category.DEFAULT" /> <data android:mimeType="vnd.android.cursor.dir/vnd.google.note" /> <action android:name="android.intent.action.GET_CONTENT" /> <data android:mimeType="vnd.android.cursor.item/vnd.google.note" /> </intent-filter>
The Main Entry when a user launches the application
Launched by other applications for list access
Launched by other applications for single item access

15. Another Android Manifest
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="
package="com.bikerolas" android:versionCode="30" android:versionName="1.2">
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
<uses-permission android:name="android.permission.ACCESS_LOCATION />
<uses-permission android:name="android.permission.ACCESS_GPS" />
<uses-permission android:name="android.permission. ACCESS_CELL_ID />
<application
android:debuggable="false">
<activity android:name=".Fling"
<intent-filter><action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" /> </intent-filter>
</activity>
<service android:name=".FlingService" />
<receiver android:name=".FlingServiceManager" android:permission="android.permission.RECEIVE_BOOT_COMPLETED">
<intent-filter><action android:name="android.intent.action.BOOT_COMPLETED" /> </intent-filter>
</receiver></application><uses-sdk android:minSdkVersion="2"></uses-sdk>
</manifest>
Note: ACCESS_LOCATION and ACCESS_GPS were used by earlier Android versions and are now deprecated

16. app.build.gradle and build.gradle
build.gradle (some of these are moved into the manifest during the build process)
Configuration parameters for building an application
Min, max, compile, target sdk versions
Version number
Dependencies
app.build.gradle
Configuration parameters for application build parameters

17. Localize Strings How? Create XML files in the res/values directory
Why? Promotes Internationalize and easier maintenance
Example (Strings.xml)
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="hello">Hello World, MyActivity!</string>
<string name="app_name">PA4AD_Ch02_Hello_World</string>
</resources>
Build: Android creates gen/<packageName>/R.java automatically from the information in res/Strings.xml
Java Access: setTitle(getText(R.string.hello));
Manifest XML Access:

18. Res directories They are not nested (no res/directory/subdirectory)
Their names give a hierarchical appearance layout, layout-en, layout-en-w720dp
Files contained in all of the variant files have the same name
Android tries the most specific one first and works backwards to the most general. If the file name is not found, it is an error

19. match_parent or wrap_content
How? Store xml text files in the res/layouts directory
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android=" android:layout_width=“match_parent" android:layout_height=“match_parent“
android:orientation="vertical" > <TextView android:layout_width=“match_parent" android:layout_height="wrap_content“
/>
</LinearLayout>
Notes
fill_parent (or match_parent Android 2.0 and later) fill the entire space of the parent layout
Wrap_content uses as little space as needed

20. Layout Components within a View
FrameLayout
Each widget must specify where it is to appear
LinearLayout
Widgets are arranged vertically or horizontally (similar to Box in Swing)
RelativeLayout
Widgets are arranged relative to the position of others within the View

21. RelativeLayout Example

22. The Java Code
package com.paad.helloworld; import android.app.Activity; import android.os.Bundle; public class MyActivity extends Activity { /** Called when the Activity is created or restarted. public void onCreate(Bundle savedState) { super.onCreate(savedState); setContentView(R.layout.main); }
A Bundle is a bunch of key/value pairs for Applications to restore their state after an Android termination

23. Debugging Techniques Tracing the execution
Start: android.os.Debug.startmethodTracing("foo");
Stop: android.os.Debug.stopMethodTracing();
Writes output to: foo.trace on the emulator or device
Log class: (Log.i, Log.d, Log.e, Log.v, Log.w)
Analogous to Java: System.out.println or Javascript: Console.log
Example: Log.v("category string", "message");
Asynchronous Alert Dialogs AlertDialog.Builder build = new AlertDialog(context); build.setTitle("Some Message"); AlertDialog ad = builder.create(); ad.show();
Breakpoints and Watch expressions: Very similar to Eclipse

24. Strict Mode (Android 2.3 and newer)
Developer tool: detects questionable operations and performs
Specified actions that flag these to facilitate correction
Report violations and IO Operations: Disk reads, disk writes, etc.
Common options when detection occurs: Write a Log message, display a dialog message, or crash the application
Example StrictMode.setVMPolicy(new StrictMode.VMPolicy.builder() .detectDiskWrites().detectLeakedSqlLiteObjects() .penaltyLog().penaltyDeath().build());
Note: The build retuns a ThreadPolicy object to the VM Policy builder
Detect if in debug mode ApplicationInfo info = getContext().getApplicationInfo(); if (info.flags & ApplicationInfo.FLAG_DEBUGGABLE) != 0) { /* code here */}